Programmable thermostat units are commonly used in cool climates for controlling electric baseboard heaters. It is desirable to further enhance the thermostat units to better manage the energy consumption in a given home or building area. For example, an interface may be added to each thermostat unit to be in communication with each other and/or with a central control system. Moreover, solid-state controls such as TRIACs are not as energy-efficient as other means of switching, making it desirable to implement a better solid-state switching solution.
However any additional electronic component or feature added to the thermostat units requires energy from the electric source in order to operate it. Further, as is known, such thermostat units are connected in a 2-wire configuration known as line-to-line, as illustrated in FIG. 1A for electric baseboard heaters. As can be seen, the 2-wire (L1 and L2) configuration does not provide a “ground” to allow for a difference of potential to exist. Therefore, it is challenging in such a configuration to provide a stable and reliable flow of energy to the circuit and/or other electronic component(s) of the thermostat. This challenge is further apparent in an “in-line” configuration, where only L1 or L2 is available to power the thermostat (i.e. L1 and L2 are connected through different electrical boxes).
Moreover, it is also desirable for the operative components to remain latent for weeks or months in order to monitor room temperature during periods of the year when heating is not needed. It is also desirable to provide an improved system which is reasonably priced, thereby limiting the hardware-based solutions. It is also desirable to provide a system which is compatible with many communication protocols and that may be retrofitted by a user, both in its physical installation and its communication systems.
Therefore, there is a need for an improved system for electric heater thermostats provided with communication module for centrally controlling the thermostats in a more energy efficient manner. Such centralized control devices are already marketed for furnace-type heating or cooling systems, but those devices are fed DC current by the equipment they are controlling, as shown in FIG. 1B. Also, there is typically a single unit in a centrally-configured system while baseboard-heating operation requires one unit per room and typically one unit per heater thus making the networking capability more important.
Known to the Applicant are U.S. Pat. No. 7,476,988 B2 (MULHOUSE et al.); U.S. Pat. No. 7,590,499 B2 (HA et al.); U.S. Pat. No. 8,523,083 B2 (WARREN et al.); U.S. Pat. No. 8,550,370 B2 (BARRETT et al.), and United States patent applications Nos. 2013/0213952 A1 (BOUTIN et al.) and 2014/0000858 A1 (FRANK).
In light of the aforementioned, there is a need for an improved system which, by virtue of its design and components, would be able to overcome some of the above-discussed prior art concerns.